Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Gas exchange and photosynthetic performance of the tropical tree Acacia nigrescens when grown in different CO2 concentrations
AU - Possell, Malcolm
AU - Hewitt, C. N.
PY - 2009
Y1 - 2009
N2 - The photosynthetic responses of the tropical tree species Acacia nigrescens Oliv. grown at different atmospheric CO2 concentrations-from sub-ambient to super-ambient-have been studied. Light-saturated rates of net photosynthesis (A (sat)) in A. nigrescens, measured after 120 days exposure, increased significantly from sub-ambient (196 mu L L-1) to current ambient (386 mu L L-1) CO2 growth conditions but did not increase any further as [CO2] became super-ambient (597 mu L L-1). Examination of photosynthetic CO2 response curves, leaf nitrogen content, and leaf thickness showed that this acclimation was most likely caused by reduction in Rubisco activity and a shift towards ribulose-1,5-bisphosphate regeneration-limited photosynthesis, but not a consequence of changes in mesophyll conductance. Also, measurements of the maximum efficiency of PSII and the carotenoid to chlorophyll ratio of leaves indicated that it was unlikely that the pattern of A (sat) seen was a consequence of growth [CO2] induced stress. Many of the photosynthetic responses examined were not linear with respect to the concentration of CO2 but could be explained by current models of photosynthesis.
AB - The photosynthetic responses of the tropical tree species Acacia nigrescens Oliv. grown at different atmospheric CO2 concentrations-from sub-ambient to super-ambient-have been studied. Light-saturated rates of net photosynthesis (A (sat)) in A. nigrescens, measured after 120 days exposure, increased significantly from sub-ambient (196 mu L L-1) to current ambient (386 mu L L-1) CO2 growth conditions but did not increase any further as [CO2] became super-ambient (597 mu L L-1). Examination of photosynthetic CO2 response curves, leaf nitrogen content, and leaf thickness showed that this acclimation was most likely caused by reduction in Rubisco activity and a shift towards ribulose-1,5-bisphosphate regeneration-limited photosynthesis, but not a consequence of changes in mesophyll conductance. Also, measurements of the maximum efficiency of PSII and the carotenoid to chlorophyll ratio of leaves indicated that it was unlikely that the pattern of A (sat) seen was a consequence of growth [CO2] induced stress. Many of the photosynthetic responses examined were not linear with respect to the concentration of CO2 but could be explained by current models of photosynthesis.
KW - Acacia
KW - Elevated CO2
KW - Nitrogen content
KW - Photosynthesis
KW - Sub-ambient CO2
KW - Water-use efficiency
KW - ATMOSPHERIC CARBON-DIOXIDE
KW - LAST GLACIAL MAXIMUM
KW - ELEVATED CO2
KW - AMAZONIAN ECOSYSTEMS
KW - CHLOROPHYLL FLUORESCENCE
KW - MESOPHYLL CONDUCTANCE
KW - STOMATAL CONDUCTANCE
KW - ISOPRENE EMISSIONS
KW - VASCULAR PLANTS
KW - INCREASING CO2
U2 - 10.1007/s00425-008-0883-1
DO - 10.1007/s00425-008-0883-1
M3 - Journal article
VL - 229
SP - 837
EP - 846
JO - Planta
JF - Planta
SN - 1432-2048
IS - 4
ER -